Concerning your thoughts on a light bullet of only 105gr. while still working with a 300gr., there is no valid reason a 10" twist would not do that.
I expect some rifles will do very well, while some do not like lighter bullets.
The same break or huge swing in bullet weights for calibre occur in the .223 ctg. Some twists as fast as 7 1/2", meant for very long .224" bullets, but the lads with those rifles, not only use them with 85 and 90gr. bullet for 1,000 yard plinking, but for shooting gophers with 40gr. Hp's or plastic tipped bullets.

Many guns seem to handle gross overstabilization (if there is such an actual thing) of their projectiles, but understabilization is not tolerated - at all.

Fair to say, they probably shoot will with the range of projectiles you mentioned.

On the other hand, when bullet are spun too quickly for their make-up, they tend to break up in the air before contact with the intended target or they disintegrate upon any contact - like little bombs. Witness our very frangible varmint bullets that cannot cope or hold together simply hitting grass or hay stalks.
Surely a 108gr. bullet in .338" diameter MUST be a varmint-type bullet, meant for approaching extreme velocities for disruptive performance on small game. Due to their light weights, they must be very short, close range bullets designed for very shallow penetration.